ISSN:0148-6071    

DOI:10.1177/0148607192016003197

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

The effect of malnutrition on the functional properties of fast‐ and slow‐twitch muscles from rats was studied using aerobic and anaerobic preparations. A 2‐day fast and hypocaloric feeding to a weight loss of 25% were used as models of malnutrition. Soleus (slow‐twitch) and extensor digitorum longus (EDL) (fast‐twitch) muscles were studied using an in situ preparation with the blood supply intact and an inuitropreparation to which cyanide had been added to render the muscles anaerobic. We found that a 2‐day fast had little effect on the function of muscles stimulated insitu,whereas anaerobic stimulation produced a decrease in force per gram of muscle weight in the soleus, but not in the EDL, compared with control values. Hypocaloric feeding resulted in a slowed relaxation rate, an increased Fs/Fmaxratio, and an upward shift of the force‐frequency curve relative to controls when studied insitu.Under anaerobic conditions, soleus muscles from hypocaloric rats continued to show a slow relaxation rate and demonstrated a loss of force per gram of muscle weight compared with controls, particularly at low stimulation frequencies. EDL muscles from hypocaloric rats had an increased relaxation rate and were able to maintain force with anaerobic stimulation. Soleus and EDL muscles from the fasted and hypocaloric groups had lower activities of phosphofructokinase. We conclude that slow‐twitch muscles from malnourished rats are at a disadvantage when required to function under anaerobic conditions. These findings suggest that muscle performance may be impaired in malnourished patients subjected to hypoxia. (Journal of Parenteral and Enteral Nutrition 16:219–225, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003219

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Polyamines, synthesized by all mammalian cells, are involved in protein and energy metabolism. We measured urinary excretion of polyamines, putrescine, spermidine, spermine, and their metabolitesN1‐acetylspermidine andN8acetylspermidine, resting energy expenditure, and nitrogen excretion in 12 depleted patients with gastrointestinal malignancy during preoperative and postoperative parenteral nutrition and in 7 patients with multiple trauma receiving similar parenteral nutrition. During preoperative nutrition support, the excretion of putrescine (p<.05) and total polyamines (p<.01) increased by 420% and 60%, respectively. Increases in energy balance and resting energy expenditure during nutrition could entirely explain the observed changes in polyamine excretion. Preoperatively, the excretion ofN1‐acetylspermidine (p<.05),N8acetylspermidine (p<.001) and total polyamines (p<.05) was higher in patients with a surgically noncurable tumor than in those with a surgically curable tumor. The energy balance and resting energy expenditure could also explain the differences in polyamine excretion between patients with surgically curable and noncurable disease, excluding the increasedN8‐acetylspermidine. Postoperatively, the excretion ofN8‐acetylspermidine in patients with multiple trauma without malignancy and in patients with palliative operation was similar, and was higher than in patients with a totally resected malignancy (p<.01). Our results suggest that the excretion of polyamines reflects the activity of energy metabolism in general and that polyamine excretion is not specific for any particular disease. (Journal of Parenteral and Enteral Nutrition 16:226–231, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003226

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Malnutrition increases the host's susceptibility to infection. However, the mechanisms are not well understood. This study examined the interaction of protein and zinc underfeeding in mice before challenge with an intracellular pathogen, Salmonellatyphimurium.C3H/HeN mice (n = 68) were weighed and placed on one of four diets: 20% ovalbumin with adequate zinc (20% NL), 20% ovalbumin without zinc (20% LO), 1% ovalbumin with zinc (1% NL), and 1% ovalbumin without zinc (1% LO). At the end of 6 weeks they were again weighed and then challenged with 104S.typhimuriumintraperitoneally. Mortality was recorded over the next 2 weeks. Although weight loss was markedly affected by protein malnutrition (two‐way analysis of variance: p =.0001), there was no independent effect by zinc (p=.3459). Similarly, protein malnutrition alone affected mortality rates (χ2:p=.0001), whereas zinc had no independent effect (p=.7166). However, both protein and zinc underfeeding shortened the length of survival (Mann‐Whitney U test: p<.001). We conclude that protein malnutrition is the dominant factor influencing weight loss and mortality in this model. However, zinc malnutrition does shorten the length of survival and may contribute to the global immunosuppression noted in malnourished subjects. (Journalof Parenteraland Enteral Nutrition16:232–235, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003232

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

The metabolic impact of infusing a large amount of leucine (Leu) or valine (Val) was examined with regard to the corrective effect of total parenteral nutrition (TPN). Rats recovering from severe sepsis received either Leu‐ or Valenriched TPN solution for 30 hours. The invivobehavior of the amino acids administered was explored by a pulse injection of14C‐labeled Leu or Val. The recovery of14CO2from Leu increased by 64% in the septic rats of Leu‐TPN group (41% of dose;p<.01), as compared with control rats receiving the same TPN solution, whereas no significant rise in the14CO2recovery from Val occurred in the septic rats given Val‐TPN (45% of dose) in comparison with the corresponding controls. The enhancement of Leu catabolism to CO2in the Leu‐TPN group was compatible with the alterations of urinary nitrogen excretion, plasma Leu level, and metabolite contents of liver and muscle. The only difference in metabolite levels observed between the two TPN groups was in hepatic total adenine nucleotides. Plasma amino acid levels were largely unaffected by infusion of these TPN solutions highly enriched with branched‐chain amino acids (45%), except for an approximately threefold elevation of the Val level in Val‐TPN rats. Thus, when administered in a large quantity during such short‐term TPN, Leu can exert its metabolic effect without causing an imbalance in plasma amino acids under severe catabolic conditions. (Journalof Parenteral and Enteral Nutrition16: 236–240, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003236

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Thirty infants were randomly assigned to receive either 3 mL of MVI‐Pediatric supplement (PAR3 group, parenterally fed) or 2 mL (PAR2 group, parenterally fed). For the first week, 100% received total parenteral nutrition (TPN), 50% by the second, and less than 33% by the third. Eighteen control infants received enteral feeds of infant formula. Baseline (before TPN) and subsequent weekly blood samples, dietary data, and 24‐hour urine collections were obtained. The adequacies of thiamine and riboflavin were assessed by the thiamine pyrophosphate effect and erythrocyte glutathione reductase activity, respectively. Urinary thiamine and riboflavin levels were measured by fluorometry. Plasma folate, red blood cell folate, urinary folate, and plasma vitamin B12concentrations were determined by radioassay. No differences between groups were observed in thiamine pyrophosphate effect, erythrocyte glutathione reductase activity, urinary B1or Bz, or red blood cell folate levels at any time. Plasma folate differed (p<.05) among the PAR3 group (24 ± 7 ng/mL), and both the PAR2 (13 ± 5 ng/mL) and enterally fed (ENT) groups (16 ± 3 ng/mL) before the initiation of feeds, at week 1 (PAR3 = 32 ± 15 ng/mL; PAR2 = 18 ± 4 ng/mL; ENT = 19 ± 9, ng/mL) and between the PAR3 (30 ± 16 ng/mL) and PAR2 (16 ± 4 ng/ mL) infants at week 2. Plasma vitamin B12levels differed among the ENT groups (551 ± 287 pg/mL) and both the parenteral groups (PAR2 = 841 ± 405 pg/mL; PAR3 = 924 ± 424 pg/mL) at week 1 and between the ENT (530 ± 238 pg/ mL) and PAR3 (999 ± 425 pg/mL) groups at week 2. From the results of the present study it appears that 2 mL of MVI‐Pediatric supplement is sufficient to meet the thiamine, riboflavin, folate, and vitamin B12needs of the low birth weight infant receiving short‐term parenteral nutrition. (Journal of Parenteral and Enteral Nutrition16:241–247, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003241

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Patients with chronic obstructive pulmonary disease (COPD) often lose weight and muscle mass with progression of the disease. Muscle protein degradation in patients with COPD has never been examined before and during hypercaloric feeding. Eight severely malnourished patients with COPD were examined at home consuming their usual intake, in the hospital after 3 days of a meat‐free regular oral diet (period B), and during a hypercaloric (55 kcal/kg) high‐lipid (55%) parenteral formula (total parenteral nutrition [TPN]). During period B, 8 well‐nourished patients and 10 malnourished cancer patients were used as control groups. Measurements included plasma assays, leg blood flow, leg exchange (of 3‐methylhistidine [3MeH], glucose, lactate, and oxygen) and urinary measures of 3MeH, creatinine, and nitrogen. During period B, net release of 3MeH across the leg in patients with COPD was similar to that in well‐nourished control subjects and cachectic cancer patients. In COPD patients, there was only a transient decrease in leg exchange values of 3MeH with administration of TPN. COPD patients demonstrated a reduction (p<.01) in urinary 3MeH excretion and an increase in nitrogen balance (p<.01) with TPN compared with period B. The decrease in muscle protein degradation with administration of TPN accounts for about 50% of the increase in nitrogen retention in patients with COPD. These data suggest that in severely malnourished patients with COPD the weight loss is not dependent on increased rates of skeletal muscle protein degradation; nevertheless, degradation rates attenuate with a positive nitrogen balance during nutrition repletion. (Journal of Parenteral and Enteral Nutrition 16: 248–254, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003248

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

The effects of pectin and cellulose on fat absorption after massive small‐bowel resection were studied in rats. Weanling Wistar rats underwent 80% resection of the small intestine with gastrostomy, and fat emulsion labeled with14C‐linoleate was given via a gastrostomy tube for the fat absorption test on the 10th postoperative day. They were classified into three groups by diet as follows: E group, a fiber‐free, chemically defined diet (CDD); EP group, CDD with 2% pectin; and EC group, CDD with 2% cellulose. The cumulative and hourly output of14C in the expired air, the absorption rate of14C in the intestine, and the metabolic utilization rate of14C were calculated. The cumulative14CO2output was significantly lower in the EC group than in the E and EP groups. However, there was no significant difference in the14CO2output between the E and EP groups. The highest hourly14CO2output in the E and EP groups was observed during the first 2 hours. However, in the EC group, this fluctuated at low levels. No significant difference in the 1‐14C‐linoleate absorption rate was observed between the E and EP groups, whereas it was significantly lower in the EC group than in the E and EP groups. The metabolic utilization rate of 1‐14C‐linoleate showed no significant difference among the three groups. These data suggest that an addition of pectin to CDD does not impair small intestinal absorption of 1‐14C‐linoleate after massive small‐bowel resection, and an addition of cellulose decreases absorption of 1‐14C‐linoleate. (Journal ofParenteraland Enteral Nutrition 16: 255–258, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003255

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

This study compares the effects of amino acid addition to an elemental liquid diet containing carbohydrates and triglycerides given either intragastrically or intravenously on the morphology and on hydrolase activities in the jejunum and ileum of adult rats. The isocaloric mixtures were administered for 4 days and control rats received an isocaloric laboratory diet orally. Independent of their content in amino acid, all mixtures given intravenously caused a drop in mucosal weight and a shortening of the height of the villi in both the jejunum and ileum. By enteral route, the addition of amino acids to a carbohydrate‐triglyceride liquid diet led to the maintenance of normal villus height (this effect being prominent in the ileum) and to a significant increase of jejunal sucrase and aminopeptidase activities when compared with the carbohydrate‐triglyceride mixture. Feeding the mixtures by parenteral route caused a significant drop of both enzyme activities. In contrast, lactase activity was generally not modified by the route of nutrient administration or by the composition of the diets. However, the absence of amino acid in the mixture given intravenously caused a specific drop of lactase activity in the ileum. Ileal sucrase activity was lowered dramatically by intragastric or intravenous feeding of the elemental diets. This effect was not modulated by the presence of amino acids. The presence of amino acids caused a significant drop of aminopeptidase activity in the ileum independently of the route of administration when compared with animals receiving the carbohydrate‐triglyceride liquid diet. The present report shows that amino acids present in the liquid diet given by either enteral or parenteral route are able to modulate the morphology and hydrolytic functions along the small intestine. Because amino acids are preferentially absorbed by the jejunum, the effects observed at the level of the ileum might be related to hormonal and/or biliopancreatic regulations. (Journal of Parenteral and Enteral Nutrition 16: 259–263, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003259

出版商:SAGE Publications    

年代:1992

数据来源: WILEY

摘要:

Central venous access for feeding catheters may prove difficult in patients who have had numerous previous central line insertions or complications. Duplex Doppler ultrasound was used to identify the anatomy and patency of major central veins in 11 patients in whom attempts at obtaining central venous access by an experienced operator had failed at least once and in 40 control subjects. Doppler ultrasound demonstrated the subclavian veins (diameter 12.5 ± 3.5 mm, mean ± SE) and internal jugular veins (11 ± 3.5 mm) in all the control subjects. In the patients, 18 of 44 veins were patent, 11 were small or had low blood flow, and 15 were thrombosed. In 7 patients who required central feeding catheter insertion, a suitable vein was identified and the catheter suitably placed, even in 3 subjects where no central vein was considered normal. Duplex Doppler ultrasonography is a useful technique for identifying veins suitable for the insertion of central venous lines when access has previously proved difficult. (Journal of Parenteral and Enteral Nutrition 16: 264–267, 1992)

ISSN:0148-6071    

DOI:10.1177/0148607192016003264

出版商:SAGE Publications    

年代:1992

数据来源: WILEY